Low-water alarm for steam-boilers.



H. A! HOKE. LOW WATER ALARM FOR STEAM BOILERS.

APPLICATION FILED MAY 5, 1911.

Lemma,

2 SHEBTS-SHEET 1.

GHQ: nu

Patented Jan. 1913.

W ine sow I H.A.HOKH LOW WATER ALARM FOR STEAM BOILERS,

APPLTGATIQN FILED MAY 5,1911.

iatented Jan. 7, 1913.

2 SHEETS-SHBET 2.

PENHSYLVANIA.

LQVf-WATEB ALARM FOR, STEAlvI-BOILERS.

implication filed May 5, 1911.

To a7! 'IlllO/IZ it will, m'mi'cr I Be it l-znown that l; Elam-1r it.llonn', a citizen of the United States reai ding at. Al- 'tcona, in thecount oi Blair and State nit? bania, have inrmitect certain newlmnroreinents in Lowimiter ilers or which the foliicat ion. n relates ingeneral steam boilers, and a to an improved and novel r automati all hegiren when the wa- '3 w-determined level.

oi the intention in the provirlnoStalitally operated low v'z steamboilers which is positive in its actioin which is simple e in it'econstruction," and which ly mounted upon a locomotive rain limiterwithout necessitating in the couatruction thereof. niesc and otherobject in view, the ntfon r nsists in certain novel combinaxnlarrangenn-nta oi the parts as will more full appear as the descriptionpro ceeda, the novel Features thereof being pointed out in the appendedclaima.

For a full understanding ot the. invention, reference try be had to thefollowing description and acei'nnpaliving drawings, in woit' ,5 end of alocomotive having the improved thetmmtat" iow water alarm mountedthereon, a portion of the boiler being broken to illuetrate more clearlythe manner of mounting the alarm. Fig. 2 is a vertical 49 Se tiionalriew through the device, the said new being on an enlarged scale. andFig. 5,

a ide elevation of the dericel correspondin}; and like parts arereterred to in tilt following description and indithe d 'awings by "ated-in all the views or k the same re'terence clniractera.

Flperith-ally describing the present: embodimenti oi the inrention, thenumeral 1 designatea the steam boiler ot' a locomotive. which may be ofany approved or conventional construction. Projecting into the interioroi the boiler 1, preferably from the top thereof. is pipe 2 whichterminates atsubstantially the low water level, the end of the. pipebeingopen to admit of water or steam pasaing freely up and down throughH9 or other steam boiler Specification of Letters Patent. Patented JQUL2', ll

Serial No. 625,388.

the pipe. As indicated upon the drawing an elbow 3 is applied to thetree end of the pipe so that the said pipe will open laterally. Theouter end of the pipe :2 com-munieates with the base ot a Y coupling-.01casting a which arranged upon the exterior of the boile", the twobranches o the said Y coupling communicating respectively with tuliailarthermostatic members and .6. The lower ends or bases: ot theae tubularthermostatic members are ehown as thrad ed into the branch openings of.the a coupling and the body portions of the aaid tn bnlar thermostaticmember-e are preferabl flattened and arranged with the major axesthereof parallel to each other. The upper end of the tubularthermostatic member 5 closed at 7 by pressing opposite sides thereoftog-ether, while the npper end of the valve 19 upon a valve stem 13.

- 'iheinner and opposing faces of the thern'iostatic members 5 and (Sare secured to the limbs of a U shaped thermostatic.memberl l in someSIlltttlJlG manner as bv means of the U bolts lfn the base of the Uahaped thermostatic member being rigidly secured to the Y conpling a ASindicated upon the drawing the base of this: member H- is clampedbetween the top'o'f the Y coupling 4 and a plate. 16, the said plate.being engaged by a nut 17 upon a bolt member 18 which extends throughboth the plate and the U Shaped member 14 and is threaded in the Ycoupling 4. The upper end of one arm of the U shaped thermostatic member14- in returned over the closed end of the tubular member as indicatedat 19. while the upper end of the opposite, arm ofthe U shaped member 14is extended laterally at 207ml engages a shoulder 21 upon the head 8.

The tubular thermostatic members a and G are constructed of some metalsuch as copper which has a high co-etlicient of expansion, whilethe Ushaped thermostatic member 14 constructed of some metal such as Wroughtiron which has a much lower co-efiicient of expanaion. With thisconstruction it will be obvious that when the thermostatic members areheated above the normal temperature the copper tubes 5 and G will expandmuch more rapidly than the limbs of the wrought iron member 14, andsince the opposite ends of the two copper tubes are engaged by un-'yieldingmbutments, this greater expansion of the copper tubes will tendto tlex the up per ends of the U shaped member 14 inwardly toward eachother.

The valve stem 13 extends outwardly beyond the head 8 where it issurrounded by a coil spring 92, the said coil spring being interposedbetween the head and a collar A cotter pin 24 is inserted through anopening in the 'valve stem for holding the collar 23 in position, andthe coil spring normally tends to hold the valve 12 upon its seat so asto shut off conmiunication between the compartment 9 and the interior ofthe head 8. The opposite end of the valve stem 13 is loosely receivedwithin the hollow shank-of a screw whiclnis threaded in one side of thehead 8. \Vheh this screw I is removed the end oi the valve stem ban heehgaged by a screw driver or other tool for grinding the valve upon itsseat. or the valve and valve stem can be slipped outof position byreuloving the collar 23 and spring- 22.

-A4i adjusting screw 26 'extends through the,

returned end ll) of theU shaped thermostatic member l4.- and alsothrough the closed upper end of the tubular member 5'), the extremity ofthe said adjusting screw normally abutting against the end of the valvestem 13. as indicated in Fig. 2.' A pair of clan'ipiutr nuts 27 aresbowm as threaded upon this. adjusting screw 26 and engaging oppositesides of the returned end 19 of the member It. the said nuts serving:

both to hold the screw 26 in an adjusted position and also to tightlyclose the upper end of the tubular member 5. 7

Under normal conditions the inner end oi the pipe 2 proiects below thesurface of the Wat r within the boiler and the said water enters thetubular thermostatic members 5 and 6 and is held therein under boilerpressure. ()wiiui to the fact, however, that these tubes are exposed tothe atmosphere. the water therein will be ctmsiderablv cooler than thewater within the boiler. The members of the thermostat are so adjustedthat under theseconditions the valve 12 is held in a closed position andctm'uuunication shut oitl between the con'ipartment t) and the interiorof the head 8. However, when the water within the boiler falls below thelevel of the open end of the pipe 52. the water within the tubularthermostats 5 and 6 will flew back into the boiler and steam will enterthe .members 5 and t). This steam will have the same temperature as thesteam within the boiler and will heat thecopper tubes 5 and 6 in such amanner as to causea rapid expansion thereof. its has been previouslyexplainechihe expansion of these copper tubes will be much greater thanthat of the thermostatic member 14, and since the ends of the coppertubes are held between unyielding abutments, the expansion thereof willflex the arms of the U shaped member 1- inwardly toward each other. Thisitem:- ing of the arms will cause the valve stem 13 to be pressedinwardlyagainst the action of the spring 23 by engagement with theadjusting screw 26, and the valve 12 will thus be unseated so as topermit the steam to enter the compartment 9 and pass through the opening10 and sound the whistle 11 or othe' alarm mechanism. The engineer beingthus notified that the water level is approaching a dangerous height,will-start his injector or pumps and force water into the boiler... Whenthe lower end of the pipe 2 is again submerged, the water will be forcedinto'tlie tubular thermostats 5 and 6 so as to agaiucool them and cause.them to straighten out into normal position. This allows the valve 12 toresent itself and the device is then ready for another operation.

llaving thus described the iuventio'n, what I claim as new and desire tosecure by Let tors Patent.

'1. A thermostatic apparatus for steam boilers comprising a supportingmember, a. U shaped member formed of metal having a. comparativelv smallco-etlicient of expansion and havingthe base thereof secured to thesupporting member. tubular thermostatic members formed of metal having acom arativelv large co-etticient of expansion and clamped to the outersides at the limbs of the U shaped member so that the said limbs of theU shaped member will be flexed inwardly when the tubular thermostaticmembers are heated to a temperature above flie -normal. means forcausing the tubular 'theihuostat'ic members to be normally filled withwater from the boiler, but to be filled with steam from the boiler whenthe water falls below a certain level, a head applied to one of thetubular thermostatic members and termed with an outlet, a valvecontrolling the outlet, a valve stem carrying the valve. and meansactuated by the opposite thermostatic member for engaging the valve steman opening the valve when the limbs.

of the U shaped member are flexed by the admission of steam to thetubular thermo static members.

9. A thermostatic apparatus for steam boilers comprising a support, a Ushaped member formed with metal having a comparativelv small coefficientof expansion and having the base thereof secured to the support. tubularthermostatic members formed of metal having a cbmparatively large coctlicient of expansion and clamped to the outer sides of the bulbs itthe U shat-aid methber so that the said limbs at the il are shapedmember will be flexed mwardly when the tubular thermostatic members areheated to a temperature above the normal,

the inner ends of the tubular thermostatic members engaging the base andone of the limbs of the U shaped member beingreturned to engage theouter end of the tubular thermostatic member secured thereto, a headapplied to the outer end of the opposite thermostatic member and formedwith an outlet opening and. a shoulder, the'end of the limb of the Ushaped member to which the said thermostatic member is secured beingextended laterally to engage the shoulder of the head, a valvecontrolling the outlet opening of the head, a valve stem carrying thevalve, and means carried by the returned limb of therU shaped member forengaging the valve stem to open the valve when the'limbs: ot' the Ushaped incinber are flexed inwardly tmvard each other.

3. A thermostatic apparatus for steam boilers including a Y coupling, apipe extending into the interior ot the boiler and terminating at thelow water level, the said pipe being in eonunut'ru-ation with the baseof the Y coupl ng! tubular thermostatic members secured inthe branchesof the Y coupling and formed of metal having a eomparativelv largeeo-ellieient or: expansion, a U shaped member having a smallerco-eilicient' of expansion, the base of the U shaped member beingsecured to the Y coupling While the limbs thereof are clamped to thesides ot' the tubular thermostatic members so as to be flexed laterallywhen the tubular thermostatic members are heated to a temperature abovethe normal, the said tubular thermostatic members being normally filledwith water from the boiler but being filled with steam from the boilerwhen the Water; reaches the low water level, and a 4 valve actuated bythe combined flexing of v the two limbs of the U shaped member.

4. A thermostatic apparatus 'for steam boilers comprising a Ycoupling,.a pipe extending from the base of the Y' coupling into 'theinterior of the boiler where, ,it terminates at the low water level ,"t'nlirtxlar thermostatic members having a cdlnparatively high co-efheientof expansion'and se cured to the branches of the Y coupling,'a U shapedmember formed of metal having a comparatively small co-eflieient ot'expan- S1011 and having the base thereof secured to h ll the Y coupling,the limbs of the U shaped member being clamped to the respective tubularthermostatic members so as to be flexed inwardly when the tubularthermostatic members are heated to a temperature above the normal, thesaid tubular thermostatic members being normally filled with water fromthe boiler, but being filled with steam from the boiler when the Waterreaches the low water level, a head applied to the outer end of one ofthe tubular thermostatic members and formed withxan outlet opening, avalve normally closing the outlet opening, a valve stem carrying thvalve. and means carried by the opoosit T tubular thermostatic memberfor eng g'nrg the valve stem upon the valve when the,

limbs of the U shaped member are flexed. In testnnony.wl1ereof Ihereunto athx signature in the presence of two witnesses.

HARRY A. Hons;

Witnesses:

N. E. Gr n, D. Lnoro CLarooMB.

